We select the parameter \(\lambda \)  by the L-curve method [1]}, [2]}.
Let \(l\)  be a parametrized curve in \(\mathbb {R}^2\) :
\( l(\lambda ) = (x(\lambda ), y(\lambda )) := (\text{log}(\mathcal {E}(\widehat{\phi _\lambda }), \text{log}(\mathcal {R} (\widehat{\phi _\lambda } )), \) 
